From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793291362; b=UTBxLh8ssNqOoYnoMmxpvT/K+Lzq9YZmVC+QPSaWKCbEhrICBbNhwqgD2B0Mw0GXy/VP 0yaAASr84cedCk8dhVNok3Tf3p2/jeGqdLgADTNIfDKgxcPY6iB8bgDbqJS9gDQ8mhvNP cD/JygrPJGUjJJ+EzHqADjuToh1xmOH7K7lnQVxki+Z/FbvAV2ESbsaZzcPc1VW/WRFYt QghS0AgN/dyxBhroMGC5pc17m/5fBNIRfyYyDUX53DIh1X7lUdzdLLXOLO/32WaJCK0Q+ O/BhcsSQz/NrJMVNkJ5c2k6FBfamCcnz5HBnPcDz//XuENfGCZq/grvO7xQ7GdgNbeg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793291362; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:X-B4-Tracking:X-Change-ID:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=93xDr8w82b19+okAmBRAJJIEwEanVvAKuiNDWCkwccU=; b=zOvNDX/KAQHN4wkZWehRDEwxQkHAiFg8J5uzy9JRGtuaCpKbXhzxOoAnO5TyBzQeuWLG H218XfBHBjqovMhpa6h607kS0Wh5pkMYps48E3VbKW1dSTJa0ka1JoOG+B7tuqx96GMzr x88KC4G39SlppXw4CcGIzuVDUzRwkxqCyjD7f4tTcYdvpcahgD6D23ofMJ2kW0wqUNqTv QYiasBFwNg9NbVhRlu5P/NIrQAGcdVO+rWWLYagCIL6M/JCh+I/rhCF8xKPsXZsAeQEZP Nw4rD959b1MFH5Cb1aPVmRAy7rHixIwoAC5nmfVmQo1agVjw3G1aqsInVXAdWsboq3g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=JV6VxyNn; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 508FC606A31A; Thu, 29 Oct 2026 16:29:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=JV6VxyNn Received: by smtp.kernel.org (Postfix) with ESMTPSA id 460A61F01816; Thu, 29 Oct 2026 16:29:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793291361; bh=93xDr8w82b19+okAmBRAJJIEwEanVvAKuiNDWCkwccU=; h=From:Date:Subject:To:Cc; b=JV6VxyNnWjqmNfds/4LUOXe2jzMABiRnDaKVUlmw8r+MF6vIciFzR9yD+uurFZqbh LkNdeYviciSyVf5rECzuje5TQmB3qZuBHNawqdrTd3tjIz2bvQ+WnQUsvCtSYt+UYc grLJFm9BZxsqbjppIB8KqxvN04daxTI6qiJCWE4KRr77ksqJLpqRNsyUDXgfymLPr/ r6HuoSWXnHnjFw2pVYw6ez3wz2V8zRAhEU8X1JmmMBJFaMH84HAxypRhdQFGhoNO6m 6Do4hSpaZEpxxaZzzuI6kkdUipDO2OMtaB40dbU1dBoupqg59dLmkWhTJLayTsEF/5 GrYMLP4UNOG4Q== From: Jeff Layton Date: Thu, 29 Oct 2026 12:28:16 -0400 Subject: [PATCH] statx: add STATX_ATTR_MULTIGRAIN_TIMESTAMP X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261029-mgtime-statx-v1-1-175b5afdf2fb@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzNDAyNL3dz0kszcVN3iksSSCl0js0QjI8s0y2TjJBMloJaCotS0zAqwcdG xtbUAKYGiuF4AAAA= X-Change-ID: 20261029-mgtime-statx-26a229f9c3b4 To: Alexander Viro , Christian Brauner , Jan Kara Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Jeff Layton X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=2097; i=jlayton@kernel.org; h=from:subject:message-id; bh=oP2L+9LClokU54StxbsCJCbiCwIJ6fU+GF/E/fV4FoI=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBq43RgzWEmuVIIKB54jXWJNr5QYNdiZaozWwMsN XgR4HDlSg+JAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCauN0YAAKCRAADmhBGVaC FTOdD/4rxg0XwgVuFc9lFXsGxeMYI6lwWI5J1dCyUFLV0j1qsVC92V4J4sx0AZnLYbaSlUxER+T PAsn9tD5RaAZmDzB+2ywDVRI1a/NUodorSOescDyukg/NqA1ee3d+TEmteEG/UeGkwPL1b7VltU kn8GmqvHmhzKD3IhWap+0L0A+72uq2UTQRd0F4NFpBXGdYc4yQZ2Q5gn/nj1Z3wnGmWdAtJeQaA vpUW45sOhpV5dwQ8M028D+CpwNYa6TXFecw2LNMuSplYgemQtdBiKfg8ll+4N78MKG01KhtSdOH JXIbbYrqdJPjEQjf1avwI8eQ34yek7XUmOgl7vqzuW/aWE+tTvi3nyJd6y6rHnedSmcRMGzuaj9 a74oEcU0ML1Mck9nc/azjsD1twDbaXgIanRzXc7vQky/T+Ojb18fZJr8yPJD7SDGh7NmSYm61XC djI7gWnwlx+DpEgjZydqsCsFnrl1Ft9E4C+4zjaF404DkwP4NJ60CGNRfwgaRGjvTZqzlKIaKaJ QSLG4LPnFtLRVhuwjEXY9ddOokeP/77xgjxd82b5zv5RY1Hgi0o8MQjM9ZYfVky5c4y7JOJ+LQ/ h/ve+bKCOzSJt2KIoYTvxpeN/eZp6jEUa9m8L4J+kyzop6WQB0tTfSfNB3MAtoG0A+MGI3CPu9T kFcS2YPwFtzxXBw== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 Userland has no way to tell whether a file's timestamps are multigrain, i.e. whether successive changes after a query are guaranteed to yield distinct timestamps. Add STATX_ATTR_MULTIGRAIN_TIMESTAMP and set it in vfs_getattr_nosec() when is_mgtime() is true (IOP_MGTIME is set from FS_MGTIME at inode init). Always advertise it in attributes_mask. Suggested-by: Christoph Hellwig Signed-off-by: Jeff Layton --- HCH suggested this when I posted the fstest for multigrain timestamps. I think it makes sense. If this looks good, I'll plan to send a manpage update for statx(2). --- fs/stat.c | 6 +++++- include/uapi/linux/stat.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/stat.c b/fs/stat.c index a2e63c6c45b7..67b9f1784b23 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -206,9 +206,13 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat, if (IS_VERITY(inode)) stat->attributes |= STATX_ATTR_VERITY; + if (is_mgtime(inode)) + stat->attributes |= STATX_ATTR_MULTIGRAIN_TIMESTAMP; + stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | STATX_ATTR_DAX | - STATX_ATTR_VERITY); + STATX_ATTR_VERITY | + STATX_ATTR_MULTIGRAIN_TIMESTAMP); idmap = mnt_idmap(path->mnt); if (inode->i_op->getattr) { diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h index 1686861aae20..b978860590b1 100644 --- a/include/uapi/linux/stat.h +++ b/include/uapi/linux/stat.h @@ -255,6 +255,7 @@ struct statx { #define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */ #define STATX_ATTR_DAX 0x00200000 /* File is currently in DAX state */ #define STATX_ATTR_WRITE_ATOMIC 0x00400000 /* File supports atomic write operations */ +#define STATX_ATTR_MULTIGRAIN_TIMESTAMP 0x00800000 /* File uses multigrain timestamps */ #endif /* _UAPI_LINUX_STAT_H */ --- base-commit: c339f4010dea8b0d754f84ace70cd1b089878ef8 change-id: 20261029-mgtime-statx-26a229f9c3b4 Best regards, -- Jeff Layton